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Discussion Starter · #1 ·
My 2015 challenger HC’s fuel system seems to be malfunctioning.

Twice the motor has died due to what I can determine to be fuel starvation. I know that the main pump is working at least, as when I fill up the tank, it will run until the tank reads a little over quarter full at which point the motor dies.

Am I right in my understanding that as the rank is a saddle design, the auxiliary pump on the right, pumps gas from the right side of the tank to the main pump’s inlet on the left side ?

That understanding being the case, would this issue of the motor dying whilst there is still over quarter tank indicated, suggest the auxiliary pump is not working, and so at some point the main pump empties the left side of the tank, but as the aux is not working it can’t empty the right?

There is a fuel level float switch on both pumps, is Aux one a cut off switch ?

Further information in support, when I fill up I’m only needing put between 45 to 50 ltrs of juice into a 70 ltr tank And as stated it indicates over quarter full when it’s died.

Any thoughts or advice would be greatly appreciated.

thanks
 

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2018 Scat Pack SHAKER in Plum Crazy- GONE :-(
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Sure sounds like a transfer issue. ¼ tank is probably left tank empty, and right tank ½. I think AlfaObd can read both levels and diagnose, but I haven't personally looked.
I think the left is the primary tank, so next time you get below ½ tank, take some roundabouts quick, and see if it sloshes to the left tank, to keep more fuel over there.
 
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The Bacon Hauler (‘12 Cop Charger)
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That sort of malfunction in the fuel system should result in some DTCs I would think. Is the CEL on? Any stored codes related to fuel/misfires?
 

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Discussion Starter · #4 ·
That sort of malfunction in the fuel system should result in some DTCs I would think. Is the CEL on? Any stored codes related to fuel/misfires?
no check engine light. I don’t have an OBD reader yet, but I don’t see any fault showing as I scroll through the Instrument panel display menus.
 

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The Bacon Hauler (‘12 Cop Charger)
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no check engine light. I don’t have an OBD reader yet, but I don’t see any fault showing as I scroll through the Instrument panel display menus.
just spitballing here, but if the engine were getting starved to the point of dying, I would expect some sort of DTC to show up.

Could this be an electrical issue? If the pump(s) is losing power or de-energizing suddenly, would that be treated differently than a fuel starvation issue?

IDK, definitely an interesting case. Keep the thread updated with whatever you figure out.
 

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Discussion Starter · #6 ·
just spitballing here, but if the engine were getting starved to the point of dying, I would expect some sort of DTC to show up.

Could this be an electrical issue? If the pump(s) is losing power or de-energizing suddenly, would that be treated differently than a fuel starvation issue?

IDK, definitely an interesting case. Keep the thread updated with whatever you figure out.
Yeah it’s got me puzzled, obviously I don’t want to tear into things and start replacing stuff needlessly, but need to pull the pumps as a minimum and check operation at the very least - I’ll update as I go - thanks for sharing your thoughts 👍
 

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Discussion Starter · #7 ·
So I eventually got around to pulling fuel pumps etc - my car is YM 2015. I was told that the hellcat’s all had pumps in both sides of the fuel tank.

Well they may do now, but I can categorically say mine doesn’t. So I’m tearing this apart expecting there to be a auxiliary pump and there isn’t one ?! I Mine has a siphon type of fuel balance, which I’m told is now discontinued. So it’s a level sender and fuel transfer tubing on one side of the tank and pumps on the other.

once into it I found siphon lines, where they connect to the body of the carrier frame, had some how become partially dislodged and so clearly was lose if suction as the level decreased and the head of fuel dropped - I’m second owner and whilst there was no evidence of any tampering with the right side, there is in the left, so assumption is that a fuel pump has been replaced at sone point and in the process, someone has pulled too hard and dislodged a fuel line from the right side, otherwise I have no clue how the pipe might have come away from the nozzle, as it quite a tight fit and there is a heavy metal clip resting two nozzles to the carrier frame.

anyway, refitted and secures, so things appear to be correct 👍
 

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2020 Dodge Challenger Hellraisin Scat Pack
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So I eventually got around to pulling fuel pumps etc - my car is YM 2015. I was told that the hellcat’s all had pumps in both sides of the fuel tank.

Well they may do now, but I can categorically say mine doesn’t. So I’m tearing this apart expecting there to be a auxiliary pump and there isn’t one ?! I Mine has a siphon type of fuel balance, which I’m told is now discontinued. So it’s a level sender and fuel transfer tubing on one side of the tank and pumps on the other.

once into it I found siphon lines, where they connect to the body of the carrier frame, had some how become partially dislodged and so clearly was lose if suction as the level decreased and the head of fuel dropped - I’m second owner and whilst there was no evidence of any tampering with the right side, there is in the left, so assumption is that a fuel pump has been replaced at sone point and in the process, someone has pulled too hard and dislodged a fuel line from the right side, otherwise I have no clue how the pipe might have come away from the nozzle, as it quite a tight fit and there is a heavy metal clip resting two nozzles to the carrier frame.

anyway, refitted and secures, so things appear to be correct 👍
Thanks for the update. Good job getting to the bottom of the problem. I read your post the other day but I had nothing to offer in the way of help.

But with hindsight I can tell you a previous car of mine had a saddle tank with two separate and unconnected basins. (This was to clear the front diff of the AWD system.) The pump was located up high and worked two siphon jets -- one for each basin -- which lifted fuel up to the pump. Some was routed to the engine the rest used to supply fuel to the siphon jets to bring fuel up to the pump. The pump worked pretty hard and the car came equipped with a fuel cooler which was fed refrigerant from the A/C system when the A/C was on to help keep the fuel and fuel pump temperature down.

While the fuel pump of course could fail -- and in the case of my car did at around 140K miles -- another problem was one of the siphon hoses would fail. Most often develop crack/split. Thus only fuel from one side of the tank could be siphoned out. The engine ran out of fuel with a half a tank left, the other basin being full because the siphon no longer worked.

Also, the fuel tank level sensor only covered the upper portion of the tank. Once the fuel level dropped below that the fuel level was determined by the engine controller based on various telemetry.

Around town I ran the fuel level down to around 1/4 tank as is my habit. But on the open road I'd fill up as the level approached half a tank just in case one of the siphon jet hoses had failed.
 

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Discussion Starter · #9 ·
Now that’s interesting, it always amazes me how ingenious these automotive design folk are, some of the solutions, once you get into them are so obvious and so elegant. Worrying thing thing for he is this siphon setup I have, it’s no longer available, or at least all the parts places I’ve visited in case I needed to replace it state it’s discontinued, so how I fix it if the joints fail in future, I don’t know ? But it’s fixed now so hopefully I won’t need to 👍
 
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